What would an account like this be worth?

30 smithing
30 strength
30 crafting
30 firemaking

 

if someone is looking for it it will be worth more to them. I would say like 3m maybe 4m at most.

my advice is to level 5 more smithing levels and check this out..http://www.sythe.org/os-pures-skillers-levels-3-69/1883907-buying-cannonball-maker.html

 

I am looking to buy them for my gold farm but not sure what to pay.

 

i would say you are probably in the wrong area. i would probably post it up here and see what skill trainers would do this for you for.
http://www.sythe.org/oldschool-runescape-skill-training/
http://www.sythe.org/oldschool-runescape-skill-training/
http://www.sythe.org/oldschool-runescape-skill-training/
Hope this helps you!!!